Make core_hostname_lookup redo the lookup when a user's IP changes.

This removes the need to do lookups in the cgiirc module. This is
useful as relying on gateways to do proper DNS checks is unreliable
and has resulted in issues like 5fc4403f62. Its more sane if we do
our own lookups.

This change has been okayed by multiple WEBIRC gateway authors so
I don't think it will cause many problems.

1 files changed, 11 insertions, 100 deletions

diff --git a/src/modules/m_cgiirc.cpp b/src/modules/m_cgiirc.cpp
index 2b80f6e5c..4c57c6fdf 100644
--- a/src/modules/m_cgiirc.cpp
+++ b/src/modules/m_cgiirc.cpp
@@ -122,10 +122,6 @@ class CommandWebIRC : public SplitCommand
 			return CMD_FAILURE;
 		}
 
-		// If the hostname is malformed then we use the IP address instead.
-		bool host_ok = (parameters[2].length() <= ServerInstance->Config->Limits.MaxHost) && (parameters[2].find_first_not_of("0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ.-") == std::string::npos);
-		const std::string& newhost = (host_ok ? parameters[2] : parameters[3]);
-
 		for (std::vector<WebIRCHost>::const_iterator iter = hosts.begin(); iter != hosts.end(); ++iter)
 		{
 			// If we don't match the host then skip to the next host.
@@ -138,12 +134,12 @@ class CommandWebIRC : public SplitCommand
 			realip.set(user, user->GetIPString());
 
 			if (notify)
-				ServerInstance->SNO->WriteGlobalSno('w', "Connecting user %s is using a WebIRC gateway; changing their IP/host from %s/%s to %s/%s.",
-					user->nick.c_str(), user->GetIPString().c_str(), user->GetRealHost().c_str(), parameters[3].c_str(), newhost.c_str());
+				ServerInstance->SNO->WriteGlobalSno('w', "Connecting user %s is using a WebIRC gateway; changing their IP from %s to %s.",
+					user->nick.c_str(), user->GetIPString().c_str(), parameters[3].c_str());
 
-			// Set the IP address and hostname sent via WEBIRC.
+			// Set the IP address sent via WEBIRC. We ignore the hostname and lookup
+			// instead do our own DNS lookups because of unreliable gateways.
 			ChangeIP(user, parameters[3]);
-			user->ChangeRealHost(newhost, true);
 			return CMD_SUCCESS;
 		}
 
@@ -153,73 +149,9 @@ class CommandWebIRC : public SplitCommand
 	}
 };
 
-
-/** Resolver for CGI:IRC hostnames encoded in ident/GECOS
- */
-class CGIResolver : public DNS::Request
-{
-	std::string theiruid;
-	LocalIntExt& waiting;
-	bool notify;
- public:
-	CGIResolver(DNS::Manager* mgr, Module* me, bool NotifyOpers, const std::string &source, LocalUser* u, LocalIntExt& ext)
-		: DNS::Request(mgr, me, source, DNS::QUERY_PTR)
-		, theiruid(u->uuid)
-		, waiting(ext)
-		, notify(NotifyOpers)
-	{
-	}
-
-	void OnLookupComplete(const DNS::Query *r) CXX11_OVERRIDE
-	{
-		/* Check the user still exists */
-		User* them = ServerInstance->FindUUID(theiruid);
-		if ((them) && (!them->quitting))
-		{
-			LocalUser* lu = IS_LOCAL(them);
-			if (!lu)
-				return;
-
-			const DNS::ResourceRecord &ans_record = r->answers[0];
-			if (ans_record.rdata.empty() || ans_record.rdata.length() > ServerInstance->Config->Limits.MaxHost)
-				return;
-
-			if (notify)
-				ServerInstance->SNO->WriteGlobalSno('w', "Connecting user %s detected as using CGI:IRC (%s), changing real host to %s", them->nick.c_str(), them->GetRealHost().c_str(), ans_record.rdata.c_str());
-
-			them->ChangeRealHost(ans_record.rdata, true);
-			lu->CheckLines(true);
-		}
-	}
-
-	void OnError(const DNS::Query *r) CXX11_OVERRIDE
-	{
-		if (!notify)
-			return;
-
-		User* them = ServerInstance->FindUUID(theiruid);
-		if ((them) && (!them->quitting))
-		{
-			ServerInstance->SNO->WriteToSnoMask('w', "Connecting user %s detected as using CGI:IRC (%s), but their host can't be resolved!", them->nick.c_str(), them->GetRealHost().c_str());
-		}
-	}
-
-	~CGIResolver()
-	{
-		User* them = ServerInstance->FindUUID(theiruid);
-		if (!them)
-			return;
-		int count = waiting.get(them);
-		if (count)
-			waiting.set(them, count - 1);
-	}
-};
-
 class ModuleCgiIRC : public Module, public Whois::EventListener
 {
 	CommandWebIRC cmd;
-	LocalIntExt waiting;
-	dynamic_reference<DNS::Manager> DNS;
 	std::vector<std::string> hosts;
 
 	static void RecheckClass(LocalUser* user)
@@ -233,37 +165,19 @@ class ModuleCgiIRC : public Module, public Whois::EventListener
 	{
 		cmd.realhost.set(user, user->GetRealHost());
 		cmd.realip.set(user, user->GetIPString());
-		ChangeIP(user, newip);
-		user->ChangeRealHost(user->GetIPString(), true);
-		RecheckClass(user);
 
-		// Don't create the resolver if the core couldn't put the user in a connect class or when dns is disabled
-		if (user->quitting || !DNS || !user->MyClass->resolvehostnames)
-			return;
+		if (cmd.notify)
+			ServerInstance->SNO->WriteGlobalSno('w', "Connecting user %s is using an ident gateway; changing their IP from %s to %s.",
+				user->nick.c_str(), user->GetIPString().c_str(), newip.c_str());
 
-		CGIResolver* r = new CGIResolver(*this->DNS, this, cmd.notify, newip, user, waiting);
-		try
-		{
-			waiting.set(user, waiting.get(user) + 1);
-			this->DNS->Process(r);
-		}
-		catch (DNS::Exception &ex)
-		{
-			int count = waiting.get(user);
-			if (count)
-				waiting.set(user, count - 1);
-			delete r;
-			if (cmd.notify)
-				 ServerInstance->SNO->WriteToSnoMask('w', "Connecting user %s detected as using CGI:IRC (%s), but I could not resolve their hostname; %s", user->nick.c_str(), user->GetRealHost().c_str(), ex.GetReason().c_str());
-		}
+		ChangeIP(user, newip);
+		RecheckClass(user);
 	}
 
 public:
 	ModuleCgiIRC()
 		: Whois::EventListener(this)
 		, cmd(this)
-		, waiting("cgiirc-delay", ExtensionItem::EXT_USER, this)
-		, DNS(this, "DNS")
 	{
 	}
 
@@ -316,15 +230,12 @@ public:
 		hosts.swap(identhosts);
 		cmd.hosts.swap(webirchosts);
 
-		// Do we send an oper notice when a m_cgiirc client has their IP/host changed?
+		// Do we send an oper notice when a m_cgiirc client has their IP changed?
 		cmd.notify = ServerInstance->Config->ConfValue("cgiirc")->getBool("opernotice", true);
 	}
 
 	ModResult OnCheckReady(LocalUser *user) CXX11_OVERRIDE
 	{
-		if (waiting.get(user))
-			return MOD_RES_DENY;
-
 		if (!cmd.realip.get(user))
 			return MOD_RES_PASSTHRU;
 
@@ -416,7 +327,7 @@ public:
 
 	Version GetVersion() CXX11_OVERRIDE
 	{
-		return Version("Enables forwarding the IP/host information from a gateway to the IRC server", VF_VENDOR);
+		return Version("Enables forwarding the real IP address of a user from a gateway to the IRC server", VF_VENDOR);
 	}
 };